TreeIterCompareFunc
Description:
public delegate int TreeIterCompareFunc (TreeModel model, TreeIter a, TreeIter b)
A GtkTreeIterCompareFunc should return a negative integer, zero, or a positive integer if a
sorts before b
, a
sorts with b
, or a
sorts after b
respectively.
If two iters compare as equal, their order in the sorted model is undefined. In order to ensure that the TreeSortable behaves as expected, the GtkTreeIterCompareFunc must define a partial order on the model, i.e. it must be reflexive, antisymmetric and transitive.
For example, if model
is a product catalogue, then a compare function for the “price” column could be one which returns
`price_of(a
) - price_of(b
)`.
Parameters:
model |
The TreeModel the comparison is within |
a |
A TreeIter in |
b |
Another TreeIter in |
user_data |
Data passed when the compare func is assigned e.g. by set_sort_func |
Returns:
a negative integer, zero or a positive integer depending on whether |